---
id: "CVE-2026-120650"
kind: "vulnerability"
aliases: ["CVE-2026-120650"]
title: "Perl CGI: missing request size limits let attackers exhaust memory and disk"
severity: "medium"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["cgi", "package", "perl", "self-hosted"]
not_affected_if: ["auth-required", "internal-only", "no-cgi-module"]
published_at: "2026-11-04T00:17:26+00:00"
first_seen_at: "2026-11-04T00:46:17+00:00"
updated_at: "2026-11-04T00:48:07+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120650", "first_seen_at": "2026-11-04T00:46:17+00:00"}]
---

# Perl CGI: missing request size limits let attackers exhaust memory and disk

The Perl CGI module before 5.00 does not enforce its POST_MAX size limit for chunked multipart bodies or multipart bodies without a boundary parameter, and it reads PUTDATA, POSTDATA and PATCHDATA uploads into memory at once. An attacker can send large or many-parameter requests to exhaust server memory, CPU and disk.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed CGI module version with `perl -MCGI -e 'print $CGI::VERSION'`
- Check whether `$CGI::POST_MAX` is set in your application code or configuration
- Find applications that use the CGI module with `grep -r "use CGI" .`

## Fix

- Perl CGI: upgrade to `5.00` or later (per the advisory's affected range, versions before 5.00)

## Timeline

- 2026-11-04T00:46:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120650

## Documents

- [fix] Patch: github.com https://github.com/leejo/CGI.pm/commit/17b838dc14d2b82ae6c7e76f66ec2c3f3b08038b.patch
- [fix] Patch: github.com https://github.com/leejo/CGI.pm/commit/277baeb74fde7bce975a7bd0a1f98dcf1b9b2050.patch
- [fix] Patch: github.com https://github.com/leejo/CGI.pm/commit/8940a74e53a41563f72813b45f99cceaaa4c92e8.patch
- [fix] Patch: github.com https://github.com/leejo/CGI.pm/commit/f3febefe63fe3881d8c3ae10fa83ca8ec950b959.patch

## From the sources

CGI versions before 5.00 for Perl allow memory, CPU and disk exhaustion via missing or unenforced request size, parameter and upload limits.

$CGI::POST_MAX defaults to no limit, and when set is not enforced for chunked multipart bodies or for the boundary line of a multipart body without a boundary= parameter. Bodies saved as PUTDATA, POSTDATA or PATCHDATA uploads are read into memory in one go, and nothing limits the number of parameters or uploads.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_